JPS5814938B2 - Pipe interior rubber support - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a pipe interior rubber support used as a cushioning material or other elastic support that is interposed between structures and other various members to provide support while buffering shock, and is generally applicable to By inserting a pipe made of strong material such as steel inside the rubber plate, the stress and strain characteristics of the rubber support can be changed to the ones shown in Figure 1 (■). The purpose is to provide excellent performance to the rubber bearing by converting it as shown.

Next, the present invention will be explained in detail using illustrated examples.

2 and 3 show a pipe interior rubber support according to an embodiment of the present invention. A plurality of steel pipes 2 for setting stress/strain characteristics, each having an open section, are kept substantially parallel to each other and to both the front and back surfaces of the rubber plate, and are spaced apart in the width direction of the rubber plate. Furthermore, a steel front plate 3 and a steel back plate 4 are arranged on both the front and back sides of the rubber plate 10, and on the side surface of the rubber plate 1 parallel to the pipe 2, a rubber lateral expansion is arranged. A thin steel plate side plate 5A having an arcuate cross section is arranged for the purpose of restraining the leakage, and the rubber plate 1, the pipe 2, the front plate 3, the back plate 4 and the side plate 5A are fixed by baking or adhesive.

When carrying out this invention, the rubber plate 1 and the vip 2 may be simply fitted together without being fixed to each other, but stable performance can be easily obtained if they are fixed to each other.

As shown in FIG. 4, the side surface of the rubber plate 1 parallel to the pipe 2 is made into a plane perpendicular to the front plate 3 and the back plate 4,
A band-shaped metal side plate 5B may be fixed to the side surface thereof, or the side plates 5A and 5B may be omitted.

Furthermore, as shown in FIG. 5, protrusions 5C and 5D that protrude inward are provided on the edges of the front plate 3 and the back plate 4 parallel to the pipe 2, and the protrusions 5C and 5D provide rubber. It may be configured to restrict the lateral bulge of the plate 1.

By converting the stress/strain characteristics of general rubber, indicated by ■ in FIG. 1, into the stress/strain characteristics indicated by ■ according to this invention, many advantages arise.

The first advantage is the elastic limit of the rubber support (■ in Figure 1).
The magnitude of the bearing stress degree 7 corresponding to point 6 on the curve can be significantly increased.

That is, as shown in FIGS. 2 and 3, the pipe 2
By incorporating these into the rubber plate 1, the forces P0 and P2 acting on the front plate 3 and back plate 4 of the rubber support in FIG. 6 are almost uniform over the entire circumference of the pipe 2 due to the action of the rubber plate 1. As shown in FIG. 7, only an axial compressive force 11 is generated on the pipe wall, and almost no bending moment or shearing force is generated.

For this reason, the pipe can support a significantly larger force than when the forces P1 e P2 acting directly on the pipe 2 are applied as shown in FIG. 8.

In addition, the rubber plate 1 as a support body shown in FIGS. Since displacement in the direction (horizontal direction) 1415 is restrained, the function of the rubber support will not be lost unless the pipe is destroyed.

A second advantage is that the elastic modulus of the rubber bearing can be significantly increased.

That is, by installing the pipe 2 inside the rubber plate 1,
In response to forces applied from the front and back directions 12.13, the rubber plate is restrained from displacing in the horizontal direction 14.15 by the pipe, so it is only allowed to displace slightly in the axial direction 16.17 of the pipe; This is extremely limited due to the high resistance at the contact surface between the pipe and the rubber.

Therefore, the rubber plate of the rubber support is pressurized with its displacement restrained in each direction, and the elastic modulus E of the rubber support (O to 7 with respect to point 6 in Figure 1) is applied. Ratio E = σ6/ε of bearing stress degree σ6 and strain amount ε6 of θ~8
6) becomes significantly larger.

In this case, the amount of increase in the elastic modulus of the rubber support is determined by the elastic modulus of the pipe in the loaded state shown in Figure 6 (related to the material, thickness, diameter, cross-sectional shape, etc. of the pipe), the length of the pipe,
It is determined by the spacing between pipes, the ratio of the area occupied by the pipes to the area occupied by the rubber plate, the thickness of the rubber support, the restraint conditions on both sides of the rubber support, etc., and by selecting these appropriately, the rubber It is also possible to have an elastic modulus several tens of times that of the case of only a plate.

The third advantage is that a considerably wide range of plasticity can be set for the stress/strain characteristics of the rubber bearing.

That is, in the stress/strain characteristics ■ in Figure 1, 6 to
Although the strain increases in the 90 section, there is a plastic region in which the stress level does not increase.

This plastic region is mainly due to plastic deformation of the pipe 2, and the range can be determined by the material, shape, diameter, thickness of the pipe, presence or absence of the filler 18 inside the pipe, its material, shape, etc.

In general rubber bearings, this plastic region corresponds to the stress and
This is completely unrecognizable as shown in the strain characteristics, and is a unique characteristic of the pipe interior rubber support of the present invention.

This pipe interior rubber support has the three advantages mentioned above, so when used as a cushioning material for an object that receives an impact, it has a small initial elasticity against an impact force below a certain level. It resists through deformation, but when the magnitude of impact force exceeds a certain limit, it allows deformation without producing a resistance force that exceeds a certain limit.

Therefore, this pipe interior rubber support has the best performance as a cushioning material.

FIG. 9 shows an example in which the rubber bearing of the present invention is used as a horizontal load bearing cushion material in a bridge girder bearing having a lower shoe and an upper shoe, and is fixed to the upper surface of a bridge abutment or pier 19. An upper shoe 22 fixed to the lower surface of the girder 21 is placed on the upper surface of the metal lower shoe 20, and upward protrusions 2 are provided on both left and right sides of the lower shoe 20.
A rubber support 24 of the present invention is interposed between the upper shoe 3 and the side surface of the upper shoe 22, and this rubber support 24 effectively acts as a cushioning material against horizontal loads.

No. 10 shows an example in which the rubber bearing of the present invention is used as a horizontal load bearing cushion material between a horizontal force bearing member fixed to a bridge girder and a horizontal force bearing box fixed to an abutment or a bridge pier. a bridge abutment or pier 1
A horizontal force bearing box 25 with a rectangular cross section that opens upward is embedded in the upper part of the beam 9, and the upper part of a horizontal force bearing member 26 made of hollow steel with a rectangular cross section is embedded and fixed in the girder 21, and its horizontal The lower part of the force-bearing member 26 is disposed within the horizontal force-bearing box 25, and the lower part of the horizontal force-bearing member 26 is located on both left and right sides of the horizontal force-bearing box or on the front, rear, left and right inner wall surfaces, and on both the left and right sides of the horizontal force-bearing member 26, as well as on the front, rear, left and right sides. Between the wall and
A rubber support 24 of the present invention is interposed, and this rubber support effectively acts as a cushioning material against horizontal loads.

The pipe interior rubber bearing of this invention has a significantly larger elastic limit than general rubber bearings, and can support a large load with a small rubber bearing. It can be applied without much change to the shape and dimensions of the shoe, and since it has a large elastic modulus, it is possible to keep the amount of displacement against the design load within the allowable value with the size of the rubber support determined by the supporting force.

On the other hand, it is difficult in terms of manufacturing and construction to make the gap between the horizontal force transmission parts of multiple bearings in a bridge completely the same for each bearing, and the size of the gap is slightly different for each bearing. A difference will occur.

Therefore, when large horizontal forces act on girders, piers, and abutments during an earthquake, or when piers and abutments are mutually displaced, abnormally large horizontal stresses occur in the bearings with the small gaps, which is dangerous. In the case of the rubber bearing of the invention, a plastic region can be set, so when a horizontal force of a certain level or more is applied to the rubber bearing installed in the small part of the gap, the rubber bearing is plastically deformed. Horizontal forces can be distributed to other bearings, thus preventing abnormally large horizontal stresses from occurring in some bearings.

The pipe interior rubber support of the present invention can also be used as an elastic support for elastically supporting any member in addition to the cushioning material of the bridge support.

According to this invention, a plurality of steel pipes 2 for setting stress/strain characteristics, which extend from one end of the rubber plate 1 to the other end and are open at both ends, are installed in the rubber plate 1. Since they are buried so that they are lined up at intervals in the width direction, the elastic limit and elastic modulus of the rubber support can be significantly increased by simple means as described above, and when the load exceeds a certain limit, Since each of the steel pipes 2 arranged at intervals in the width direction of the rubber plate receives a strong compressive force and undergoes plastic deformation, it is possible to set a fairly large range of plasticity in the stress/strain characteristics of the rubber support. In particular, in the case of the present invention, a plurality of steel pipes 2 for setting stress/strain characteristics, which are open at both ends, extend from one end of the rubber plate 1 to the other end and extend in the width direction of the rubber plate. Because they are buried at intervals, the load acting on the rubber support can be widely distributed and transmitted to each steel pipe 2, and the compressive force and plastic deformation characteristics are uniform over the entire length of the steel pipe. Effects such as being able to have the following effects can be obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the stress/strain characteristics of the pipe interior rubber support of the present invention and a general rubber plate, FIG. 2 is a perspective view of the pipe interior rubber support according to an embodiment of the invention, and FIG. 4 and 5 are perspective views of a rubber support inside a pipe according to another embodiment of the present invention, and FIG. 6 shows a state in which the force applied to the rubber support acts on the entire circumference of the pipe. Figure 7 is a diagram showing the state in which compressive force is applied to the pipe, Figure 8 is a diagram showing the state in which an external force is directly applied to the pipe, and Figure 9 is the rubber support of the present invention. Fig. 10 is a longitudinal sectional front view showing an example in which the rubber bearing of the present invention is used as a cushioning material for horizontal load bearing in a bridge girder support having a lower shoe and an upper shoe. FIG. 3 is a longitudinal sectional side view showing an example in which the cushion material is used as a horizontal load bearing cushion between a member and a horizontal force bearing box fixed to an abutment or a pier. In the figure, 1 is a rubber plate, 2 is a steel pipe for setting stress/strain characteristics, 3 is a steel front plate, 4 is a steel back plate, 5A and 5B are steel side plates, and 5C and 5D are protrusions. .

Claims (1)

[Claims] 1 Inside the rubber plate 1, there are a plurality of stresses that extend from one end of the rubber plate 1 to the other end and are open at both ends.
A pipe-interior rubber support, characterized in that steel pipes 2 for setting strain characteristics are buried so as to be lined up at intervals in the width direction of the rubber plate.